Heavily armed police in Adelaide are hunting a wanted criminal who fled from officers after they tried to stop a car this morning.

Former prison guard Rodney Ian Clavell, 46, jumped from the car with another man at the corner of Gilles and Osmond Streets in the city after police had tried to stop it in nearby Angas Street.

Clavell has a long criminal history and is wanted for offences including breaching a firearms ban.

Police say the driver of the blue Ford sedan seemed to be a man of Asian appearance, in a blue hoodie and carrying a black backpack.

Clavell was believed to be the passenger and was in a white T-shirt.

Two schools, Pulteney Grammar and Gilles Street primary, were locked down during the search of the area but the emergency measure was lifted just after midday when the immediate area was declared safe.

Pulteney principal Anne Dunstan had sent a text message to families assuring them children all were safe.

Text message sent to Pulteney families

"Please be advised that the school is placed in lockdown. SAPOL monitoring situation. All students are safe and accounted for due to our quick activation of emergency procedures. We will advise as soon as further information comes to hand. Mrs Anne Dunstan, Principal"